Cortisol axis abnormalities early after stroke--relationships to cytokines and leptin

Abstract

Objective: To assess the relationships between circulating levels of proinflammatory cytokines and adrenocortical hormones and leptin early after stroke.

Design: Blood samples were collected four times daily the first two days after stroke, twice daily the next 4 days and four times at day 7. Cognitive function and functional outcome was measured at admittance and at day 7.

Setting: Consecutive inclusion of patients admitted to the stroke unit at Umeâ University Hospital.

Subjects: Eight men and 4 women with acute stroke and 10 healthy volunteers.

Main outcome measures: Levels and diurnal variations of plasma proinflammatory cytokines interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha), serum adrenocortical hormones (cortisol and DHEA) and leptin, and MMSE, SSS, and ADL scores.

Results: A significant correlation was present between IL-6 and cortisol levels the first two days after stroke (P < 0.05). In patients with a disturbed diurnal rhythm of cortisol, cortisol and leptin levels were increased (68% and 81% increase, respectively), whilst DHEA levels were unaltered. Half of the patients displayed an abnormal diurnal rhythmicity of leptin at the end of the week. Median TNF-alpha levels for the first two days after stroke also correlated to median leptin levels at the end of the week (P < 0.05). Median IL-6 levels correlated to severity of paresis on days 1 and 7 and to MMSE scores on day 7 (P < 0.05).

Conclusions: Neuroendocrine disturbances are common and often profound early after stroke. Cytokines seem to be important modulators of these disturbances, including diurnal rhythmicity of cortisol and leptin.